Sinn Fein President Gerry Adams signs an autograph for a boy while campaigning in Dundalk, County Louth, on February 23, 2011 ahead of Ireland's General Election. Adams has resigned from his positions at the Northern Ireland Assembly and Westminster in the hope of winning the Louth seat. Ireland's general election kicked off on February 23 in the Atlantic Ocean as voters on remote, windswept islands off the rugged west coast began casting their ballots two days early. The islands off Counties Donegal, Mayo and Galway traditionally vote early as bad weather often delays getting the ballot boxes back to the mainland count centres. AFP PHOTO/Leon Neal (Photo credit should read LEON NEAL/AFP/Getty Images)

Sinn Fein President Gerry Adams speaks to the media at the front gates of Hillsborough Castle in Hillsborough, Northern Ireland on January 29, 2010. The talks are being held in an attempt to find agreement between Sinn Fein and the DUP on the devolution of policing and justice powers to Stormont. AFP PHOTO/ Peter Muhly (Photo credit should read PETER MUHLY/AFP/Getty Images)

WASHINGTON - MARCH 17: U.S. Secretary of State Hillary Clinton meets with Sinn Fein President, Gerry Adams at the State Department on March 17, 2009 in Washington, DC. Adams is in Washington for St. Patricks Day and later today will also meet with U.S. President Barack Obama. (Photo by Mark Wilson/Getty Images)

SAN FRANCISCO - NOVEMBER 13: Gerry Adams, Irish President of Sinn Fein, holds a press conference November 13, 2008 on Treasure Island in San Francisco, California. Adams is in San Francisco to speak about the current Irish peace process. (Photo by Kimberly White/Getty Images)

President of Sinn Fein Gerry Adams (C) helps to carry the coffin of Martin Meehan as he is escorted by the Republican colour guard during a funeral procession in Belfast, in Northern Ireland, 06 November 2007. Martin Meehan, who died from a heart attack last Saturday, was a prominent member of the IRA who in his latter years embraced the Irish peace process after decades as a symbol of unflinching republican militancy. AFP PHOTO/Peter Muhly (Photo credit should read PETER MUHLY/AFP/Getty Images)

DUBLIN (AP) - Sinn Fein leader Gerry Adams remained in police custody for a second day Thursday as detectives questioned him over his alleged role in the Irish Republican Army's abduction, killing and secret burial of a Belfast mother of 10 in 1972.

Senior politicians in Adams' Irish nationalist party said they hoped he would be released soon without charge and accused British authorities of timing Wednesday's arrest to undermine Sinn Fein's campaigning in elections taking place in both parts of Ireland later this month.

Under Northern Ireland's anti-terrorist law Adams can be held until Friday night, by which time police must release or charge him, or seek a judicial extension to his custody.

Adams, 65, has always denied any role in the outlawed IRA, but every credible history of the Sinn Fein-IRA movement has identified him as a senior commander since the early 1970s. The IRA killed nearly 1,800 people from 1970 to 1997, when it ceased fire to permit Sinn Fein to pursue peace negotiations with Britain and leaders of Northern Ireland's Protestant majority.

Former IRA members interviewed for a Boston College-commissioned research project have linked him to the slaying of Jean McConville, a 38-year-old widow whom the IRA branded a British spy. An investigation by Northern Ireland's Police Ombudsman said there was no evidence that she was an informant.

Northern Ireland police successfully sued in U.S. courts to acquire several tapes of IRA members, and have already used them to charge Adams' alleged former Belfast IRA colleague, 77-year-old Ivor Bell, with aiding McConville's killers.

The IRA did not admit killing her until 1999, and her remains - including a skull bearing a single gunshot wound to the back of the head - was found in 2003 near a Republic of Ireland beach.

Michael McConville, a son of the dead woman, said the children know the names of some of the IRA men who abducted their mother, but "I wouldn't tell the police."

"Me or one of my family members or one of my children would get shot by these people. People think this (IRA threat) has gone away. It hasn't," McConville said. "Splinter groups of the IRA would class you as an informant and shoot you."